日時：	15:00 - 16:30, June 4 (Tue), 2024
場所：	Room 501, 5th floor, Bldg. #3 Institute for Life and Medical Sciences, Kyoto University
演者：	Yusuke Mii, Ph.D. Laboratory of Developmental Systems (Eiraku Lab.) Institute for Life and Medical Sciences, Kyoto Univ.
演題：	Wnt is essential for self-organization of planar cell polarity (PCP) not via its global gradient but via local molecular interactions with core PCP components.

講演要旨

Planar cell polarity (PCP) is the coordinated orientation of cells in a tissue plane and is
established by the asymmetric localization of core PCP components. Wnt, a family of
secreted signaling proteins, directs PCP in vertebrates, such that the polarity of each cell
appears to be aligned along the concentration gradient of Wnt. However, it remains unclear
whether Wnt actually forms a global gradient in PCP formation and how Wnt directs polarity.
In addition, the global gradient model has some theoretical problems: the gradient must be
shallow to cover the entire tissue, but in a shallow gradient, cells must be sensitive enough
to read small differences in concentration between their both ends. If cells are sensitive
enough, the gradient must be very smooth and precise, which is unlikely given the precision
of patterning by morphogens, including Wnt. Here we show that endogenous Wnt11 does
not form a gradient from the posterior source region, but rather colocalizes with core PCP
components in the neural plate of Xenopus embryos. This is because core PCP components
regulate the polarized localization of Wnt11. Furthermore, Wnt11 and core PCP components
form multiple positive feedback mechanisms to generate PCP. Thus, we propose that local
interactions between Wnt11 and core PCP components can establish PCP in a selforganizing
manner.(Language: English)

contact: Atsushi Mochizuki
Laboratory of Mathematical Biology,
Institute for Life and Medical Sciences, Kyoto University
Email: mochi*infront.kyoto-u.ac.jp(*→＠)
Tel: 075-751-4612